>>19752559Assuming you didn't wait for Shroomish to learn Spore before evolving it, Breloom joins your wreck squad with STAB Mach Punch right off the bat, along with a higher Attack stat than Gyarados. Keep it up with level-up moves and physical TMs, and you can easily solo the game with Breloom and Breloom alone (though Winona's Skarmory might be a bit of an issue).
If ORAS keeps the encounter tables from Emerald, though, Breloom's early-game beatstick skills are going to get BTFO by Marill. Evolves to Azumarill at level 18, and learns Aqua Tail at level 22 or so. It doesn't get Play Rough until level 45, but Huge Power Aqua Tail + [Normal move] means that you won't really need it until then.